Rear brake caliper piston wedged (1 Viewer)

[Trunk Monkey]

Was replacing rear rotors on my truck, had the caliper off and sitting on the axle. When buttoning things back up, noticed the piston was almost all the way out of the caliper and was wedged a little off angle. Tried tapping/coaxing it back in with a c-clamp, no luck. Removed the brake line and took the caliper to the bench, was able to easily jiggle the piston out of the caliper. Tried reassembling, it slid in fairly easily, but when trying to push it back out, it appeared to wedge again. Ordered a new caliper ($$ ouch) and later on dinked around with the existing one some more and it all went back together fine. Reinstalled on truck, brakes work fine.

I don't know if while it was off in the first place my son that was helping me accidentally hit the brakes and "popped" the piston out. Safety tells me to go ahead and replace the caliper, my wallet says the current one is working so leave it. Thoughts? Everything on the piston and all the gaskets look fine, no visible damage, no leaking fluid.

Also odd, I noticed in parts diagrams and FSM, there's two copper gaskets, one on each side of the banjo bolt, mine only had one on the caliper side.

 

[CorporalClegg]

You will certainly need a copper crush washer on both sides of the banjo fitting, if the bore of the caliper was clean and didn't have signs of wear and the piston itself is clean ( free of burs scratches gouging anything felt with finger nail) it should be fine. Given the seals are in good shape and holding.

What can also happen if both calipers are off and you compress one side with the system sealed the adjacent piston can be pushed out from the fluid pressure. It is usually recommended that you open bleeder valves when compressing pistons to avoid this and master cylinder from flipping a seal.

 

[Trunk Monkey]

Yeah, I had the reservoir cap off, still wouldn't budge. Then tried with the bleeder open, still nope. We hadn't started on the other side yet either. Can't figure out what caused it to extend and wedge. All I can think is he got in and inadvertently stepped on the brakes, caused it to pop out with some force and wedge.

Will def. get the other copper gasket on, it was dripping brake fluid after buttoning things up until I tightened things uncomfortably tight.

And - F the PS e-brake star adjuster. The DS one, piece of cake, but for some reason the PS one, you must have to go in a zen trance horse whisperer state to get that one.

 

[CorporalClegg]

That is certainly a possibility, I've done it. It's a habit to sit down and put your foot on the pedal though the piston usually ends up on the floor with my luck ..

 

[bigredmachine]

Will def. get the other copper gasket on, it was dripping brake fluid after buttoning things up until I tightened things uncomfortably tight.

skip the copper gaskets and get the factory crush washers, the aftermarket crush washers are usually pretty hard, just copper coated and usually dont seal very well